Java.Util Namespace

Classes

AbstractCollection

This class provides a skeletal implementation of the Collection interface, to minimize the effort required to implement this interface.

AbstractList

This class provides a skeletal implementation of the List interface to minimize the effort required to implement this interface backed by a "random access" data store (such as an array).

AbstractMap

This class provides a skeletal implementation of the Map interface, to minimize the effort required to implement this interface.

AbstractMap.SimpleEntry

A key-value mapping with mutable values.

AbstractMap.SimpleImmutableEntry

An immutable key-value mapping.

AbstractQueue

This class provides skeletal implementations of some Queue operations.

AbstractSequentialList

This class provides a skeletal implementation of the List interface to minimize the effort required to implement this interface backed by a "sequential access" data store (such as a linked list).

AbstractSet

This class provides a skeletal implementation of the Set interface to minimize the effort required to implement this interface.

ArrayDeque

Resizable-array implementation of the Deque interface.

ArrayList

Resizable-array implementation of the List interface.

Arrays

This class contains various methods for manipulating arrays (such as sorting and searching).

Base64

This class consists exclusively of static methods for obtaining encoders and decoders for the Base64 encoding scheme.

Base64.Decoder
Base64.Encoder
BitSet

This class implements a vector of bits that grows as needed.

Calendar

The <code>Calendar</code> class is an abstract class that provides methods for converting between a specific instant in time and a set of #fields calendar fields such as <code>YEAR</code>, <code>MONTH</code>, <code>DAY_OF_MONTH</code>, <code>HOUR</code>, and so on, and for manipulating the calendar fields, such as getting the date of the next week.

Calendar.Builder
Collections

This class consists exclusively of static methods that operate on or return collections.

Comparator
ConcurrentModificationException

This exception may be thrown by methods that have detected concurrent modification of an object when such modification is not permissible.

Currency

Represents a currency.

Date

The class <code>Date</code> represents a specific instant in time, with millisecond precision.

Dictionary

The <code>Dictionary</code> class is the abstract parent of any class, such as <code>Hashtable</code>, which maps keys to values.

DoubleSummaryStatistics

A state object for collecting statistics such as count, min, max, sum, and average.

DuplicateFormatFlagsException

Unchecked exception thrown when duplicate flags are provided in the format specifier.

EmptyStackException

Thrown by methods in the <code>Stack</code> class to indicate that the stack is empty.

EnumMap

A specialized Map implementation for use with enum type keys.

EnumSet

A specialized Set implementation for use with enum types.

EventListenerProxy

An abstract wrapper class for an EventListener class which associates a set of additional parameters with the listener.

EventObject

The root class from which all event state objects shall be derived.

FormatFlagsConversionMismatchException

Unchecked exception thrown when a conversion and flag are incompatible.

FormattableFlags

FomattableFlags are passed to the Formattable#formatTo Formattable.formatTo() method and modify the output format for Formattable Formattables.

Formatter

An interpreter for printf-style format strings.

Formatter.BigDecimalLayoutForm

The enumeration giving the available styles for formatting very large decimal numbers.

FormatterClosedException

Unchecked exception thrown when the formatter has been closed.

GregorianCalendar

<code>GregorianCalendar</code> is a concrete subclass of <code>Calendar</code> and provides the standard calendar system used by most of the world.

HashMap

Hash table based implementation of the Map interface.

HashSet

This class implements the Set interface, backed by a hash table (actually a HashMap instance).

Hashtable

This class implements a hash table, which maps keys to values.

IdentityHashMap

This class implements the Map interface with a hash table, using reference-equality in place of object-equality when comparing keys (and values).

IllegalFormatCodePointException

Unchecked exception thrown when a character with an invalid Unicode code point as defined by Character#isValidCodePoint is passed to the Formatter.

IllegalFormatConversionException

Unchecked exception thrown when the argument corresponding to the format specifier is of an incompatible type.

IllegalFormatException

Unchecked exception thrown when a format string contains an illegal syntax or a format specifier that is incompatible with the given arguments.

IllegalFormatFlagsException

Unchecked exception thrown when an illegal combination flags is given.

IllegalFormatPrecisionException

Unchecked exception thrown when the precision is a negative value other than -1, the conversion does not support a precision, or the value is otherwise unsupported.

IllegalFormatWidthException

Unchecked exception thrown when the format width is a negative value other than -1 or is otherwise unsupported.

IllformedLocaleException

Thrown by methods in Locale and Locale.Builder to indicate that an argument is not a well-formed BCP 47 tag.

InputMismatchException

Thrown by a <code>Scanner</code> to indicate that the token retrieved does not match the pattern for the expected type, or that the token is out of range for the expected type.

IntSummaryStatistics

A state object for collecting statistics such as count, min, max, sum, and average.

InvalidPropertiesFormatException

Thrown to indicate that an operation could not complete because the input did not conform to the appropriate XML document type for a collection of properties, as per the Properties specification.

LinkedHashMap

Hash table and linked list implementation of the Map interface, with predictable iteration order.

LinkedHashSet

Hash table and linked list implementation of the Set interface, with predictable iteration order.

LinkedList

Doubly-linked list implementation of the List and Deque interfaces.

List
ListResourceBundle

<code>ListResourceBundle</code> is an abstract subclass of <code>ResourceBundle</code> that manages resources for a locale in a convenient and easy to use list.

Locale

Locale represents a language/country/variant combination.

Locale.Builder
Locale.Category
Locale.FilteringMode
Locale.LanguageRange
LongSummaryStatistics
Map
MapEntry
MissingFormatArgumentException

Unchecked exception thrown when there is a format specifier which does not have a corresponding argument or if an argument index refers to an argument that does not exist.

MissingFormatWidthException

Unchecked exception thrown when the format width is required.

MissingResourceException

Signals that a resource is missing.

NoSuchElementException

Thrown by various accessor methods to indicate that the element being requested does not exist.

Objects

This class consists of static utility methods for operating on objects, or checking certain conditions before operation.

Observable

This class represents an observable object, or "data" in the model-view paradigm.

Optional

A container object which may or may not contain a non-null value.

OptionalDouble

A container object which may or may not contain a double value.

OptionalInt

A container object which may or may not contain a int value.

OptionalLong

A container object which may or may not contain a long value.

PriorityQueue

An unbounded priority Queue queue based on a priority heap.

Properties

The Properties class represents a persistent set of properties.

PropertyPermission

Legacy security code; do not use.

PropertyResourceBundle

<code>PropertyResourceBundle</code> is a concrete subclass of <code>ResourceBundle</code> that manages resources for a locale using a set of static strings from a property file.

Random

An instance of this class is used to generate a stream of pseudorandom numbers.

ResourceBundle

Resource bundles contain locale-specific objects.

ResourceBundle.Control

ResourceBundle.

Scanner

A simple text scanner which can parse primitive types and strings using regular expressions.

ServiceConfigurationError

Error thrown when something goes wrong while loading a service provider.

ServiceLoader

A simple service-provider loading facility.

Set
SimpleTimeZone

<code>SimpleTimeZone</code> is a concrete subclass of <code>TimeZone</code> that represents a time zone for use with a Gregorian calendar.

Spliterator
Spliterators

Static classes and methods for operating on or creating instances of Spliterator and its primitive specializations Spliterator.OfInt, Spliterator.OfLong, and Spliterator.OfDouble.

Spliterators.AbstractDoubleSpliterator
Spliterators.AbstractIntSpliterator
Spliterators.AbstractLongSpliterator
Spliterators.AbstractSpliterator
Spliterators.AbstractSpliterator.InterfaceConsts
SplittableRandom

A generator of uniform pseudorandom values applicable for use in (among other contexts) isolated parallel computations that may generate subtasks.

Stack

The <code>Stack</code> class represents a last-in-first-out (LIFO) stack of objects.

StringJoiner
StringTokenizer

The string tokenizer class allows an application to break a string into tokens.

Timer

A facility for threads to schedule tasks for future execution in a background thread.

TimerTask

A task that can be scheduled for one-time or repeated execution by a Timer.

TimeZone

<code>TimeZone</code> represents a time zone offset, and also figures out daylight savings.

TooManyListenersException

The <code> TooManyListenersException </code> Exception is used as part of the Java Event model to annotate and implement a unicast special case of a multicast Event Source.

TreeMap

A Red-Black tree based NavigableMap implementation.

TreeSet

A NavigableSet implementation based on a TreeMap.

UnknownFormatConversionException

Unchecked exception thrown when an unknown conversion is given.

UnknownFormatFlagsException

Unchecked exception thrown when an unknown flag is given.

UUID

A class that represents an immutable universally unique identifier (UUID).

Vector

The Vector class implements a growable array of objects.

WeakHashMap

Hash table based implementation of the Map interface, with <em>weak keys</em>.

Interfaces

ICollection

The root interface in the collection hierarchy.

IComparator

A comparison function, which imposes a total ordering on some collection of objects.

IDeque

A linear collection that supports element insertion and removal at both ends.

IEnumeration

An object that implements the Enumeration interface generates a series of elements, one at a time.

IEventListener

A tagging interface that all event listener interfaces must extend.

IFormattable

Classes that handle custom formatting for the 's' specifier of Formatter should implement the Formattable interface.

IIterator

An iterator over a collection.

IList

An ordered collection (also known as a sequence).

IListIterator

An iterator for lists that allows the programmer to traverse the list in either direction, modify the list during iteration, and obtain the iterator's current position in the list.

IMap

An object that maps keys to values.

IMapEntry

Map.Entry is a key/value mapping contained in a Map.

INavigableMap

A SortedMap extended with navigation methods returning the closest matches for given search targets.

INavigableSet

A SortedSet extended with navigation methods reporting closest matches for given search targets.

IObserver

A class can implement the <code>Observer</code> interface when it wants to be informed of changes in observable objects.

IPrimitiveIterator

A base type for primitive specializations of Iterator.

IPrimitiveIteratorOfDouble
IPrimitiveIteratorOfInt
IPrimitiveIteratorOfLong
IQueue

A collection designed for holding elements prior to processing.

IRandomAccess

Marker interface used by List implementations to indicate that they support fast (generally constant time) random access.

ISet

A collection that contains no duplicate elements.

ISortedMap

A Map that further provides a <em>total ordering</em> on its keys.

ISortedSet

A Set that further provides a total ordering on its elements.

ISpliterator

Enums

CalendarField

Enumerates values returned by several types and taken as a parameter of several types.

CalendarStyle

Enumerates values returned by several types.

FormatFlags

Enumerates values returned by several types and taken as a parameter of the F:Java.Util.IFormattable.FormatTo member.

SpliteratorCharacteristics
TimeZoneKind

Enumerates values returned by several types.

TimeZoneStyle

Enumerates values returned by several types and taken as a parameter of the F:Java.Util.TimeZone.GetDisplayName, and F:Java.Util.TimeZone.GetDisplayName members.